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The African gerbils of the genus Tatera are widespread and abundant throughout sub-Saharan Africa. There is still today a certain
controversy concerning the taxonomy of these rodents and very few attempts have been made to assess their systematic relationships.
The present paper introduces Wndings based on the partial sequences of cytochrome b (495 bp) and the 16S rRNA
(469 bp) mitochondrial genes of six (T. robusta, T. nigricauda, T. vicina, T. leucogaster, T. valida, and T. kempi) species together
with two additional taxa. We also report the karyotypes of T. vicina and T. leucogaster. We propose that T. vicina should be considered
as a valid species and show the monophyly of the robusta species group, with the exclusion of T. leucogaster. Our results
show there is a diVerent chromosomal evolutionary pattern within the two major lineages, which is recognizable through molecular
phylogenetics. One is characterized by karyotype stability and the other by a considerable number of chromosomal rearrangements.
The lineage divergence coincides with the formation of the East African Rift. The processes that led to the origin of the East
African species seem to be related to the subsequent climatic changes, which caused cyclic contraction and expansion of the savannah
biomes. Furthermore, geological activities that characterized East Africa during Plio-Pleistocene may also have contributed to
lineage divergence. |
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